Revolutionizing drug formulation development: The increasing impact of machine learning.

Over the past few years, the adoption of machine learning (ML) techniques has rapidly expanded across many fields of research including formulation science. At the same time, the use of lipid nanoparticles to enable the successful delivery of mRNA vaccines in the recent COVID-19 pandemic demonstrated the impact of formulation science. Yet, the design of advanced pharmaceutical formulations is non-trivial and primarily relies on costly and time-consuming wet-lab experimentation. In 2021, our group published a review article focused on the use of ML as a means to accelerate drug formulation development. Since then, the field has witnessed significant growth and progress, reflected by an increasing number of studies published in this area. This updated review summarizes the current state of ML directed drug formulation development, introduces advanced ML techniques that have been implemented in formulation design and shares the progress on making self-driving laboratories a reality. Furthermore, this review highlights several future applications of ML yet to be fully exploited to advance drug formulation research and development.

Data evaluating triamcinolone acetonide and triamcinolone hexacetonide loaded poly(δ-valerolactone-co-allyl-δ-valerolactone) microparticles.

Advanced drug delivery strategies can be used to enhance the therapeutic effectiveness of locally delivered corticosteroids. Poly(δ-valerolactone-co-allyl-δ-valerolactone) microparticles (PVL-co-PAVL MPs) were evaluated for delivery of two corticosteroids, triamcinolone acetonide and triamcinolone hexacetonide. PVL-co-PAVL MPs were prepared using a modified oil-in-water emulsification method, followed by a UV-initiated cross-linking process. The resulting PVL-co-PAVL MPs were purified with an excess amount of water and then acetone to remove residual surfactant, cross-linker, and catalyst before lyophilization. Triamcinolone acetonide and triamcinolone hexacetonide were independently loaded into the resulting PVL-co-PAVL MPs via a post-loading swelling-equilibrium method. The drug-loaded MPs were characterized in terms of drug loading (determined by high-performance liquid chromatography, HPLC), thermal properties (determined by differential scanning calorimetry, DSC), and in vitro drug release kinetics (with quantification of drug using HPLC) to better understand the suitability of PVL-co-PAVL MPs for delivery of corticosteroids. These data demonstrate the potential of PVL-co-PAVL MPs as a promising drug delivery platform for the sustained release of corticosteroids. Raw data have been made available on Mendeley Data. Additional details on PVL-co-PAVL MPs were previously reported [1].

Poly(δ-valerolactone-co-allyl-δ-valerolactone) cross-linked microparticles: Formulation, characterization and biocompatibility.

A novel polymeric material, poly(δ-valerolactone-co-allyl-δ-valerolactone) (PVL-co-PAVL), was used to manufacture microparticles (MPs) for sustained drug delivery. PVL-co-PAVL MPs were formulated using a modified oil-in-water approach, followed by a UV-initiated cross-linking process. Prepared MPs had a smooth spherical morphology and cross-linking of the copolymer was found to improve the integrity and thermal stability of the MPs. Paclitaxel (PTX) was successfully loaded into the MPs at a high drug loading capacity, using a post-loading swelling-equilibrium method. In vitro evaluation showed that the PVL-co-PAVL MPs provide sustained release of PTX, which exhibited first-order release kinetics. A subsequent pilot pharmacokinetic study was carried out on the PTX-loaded PVL-co-PAVL MPs. During this study, serum levels of PTX were monitored following subcutaneous administration of the MPs to Sprague-Dawley rats. Overall, the in vivo release of PTX from the MPs was lower than expected based on the in vitro release studies. Detectable serum levels of PTX suggest that sustained release of drug was achieved in vivo. Minimal changes in subcutaneous tissue were observed at the site of injection. Future studies will further examine the localized and systemic distribution of drug following administration in this new polymer-based MP system.

Cross-linked valerolactone copolymer implants with tailorable biodegradation, loading and in vitro release of paclitaxel.

Implantable drug delivery systems, formed from degradable and non-degradable polymers, can offer several advantages over traditional dosage forms for sustained drug delivery. The majority of degradable implant systems developed to date are composed of poly(lactide-co-glycolide) (PLGA). However, PLGA-based systems are not suitable for the delivery of all drugs. Each drug is unique in terms of physico-chemical properties, and polymer-drug compatibility plays a significant role in determining a drug formulation's performance. In this study, two novel cross-linkable δ-valerolactone-based copolymers were synthesized and used to prepare cross-linked disc-shaped implants. The manipulation of the composition of the discs and conditions used during drug loading were found to influence various aspects of the delivery system performance including the degree of swelling, degradation, drug-loading and in vitro release. The polymeric discs resulted in no adverse effects following subcutaneous implantation in naïve rats. These studies support further development of cross-linkable valerolactone matrices as implantable formulations for sustained drug delivery.